Research On Forming Simulation And Test Of Stamping Welded Hydrodynamic Torque Converter

Stamping welded hydrodynamic torque converter is the core component ofhydrodynamic automatic transmission (AT), which is mostly applied in the market ofvehicles with automatic transmission. Therefore, in automobile industry, hydrodynamictorque converter becomes the largest user. In recent years, although domestic automobilemanufacturer has launched new cars that are equipped with AT, the AT and its corecomponents mainly rely on the imported product, and mostly apply foreign technologies toassemble before producing in China. Since the performance and structure of hydrodynamictorque converter have a great influence on the power performance and fuel economy ofvehicle, so developing a hydrodynamic torque converter with our own intellectual propertyrights has excellent application prospect.Die manufacture is a key step in the process of designing and developing stampingwelded hydrodynamic torque converter, and the process and accuracy of manufacturedirectly impact the working performance of hydrodynamic torque converter. During theprocess of manufacturing die, it is necessary for the developers to efficiently control thespringback, which is generated by sheet forming and is also an inevitable phenomenon. Inthe area of sheet forming, springback may cause difficulties of matching the size and shapeof parts under the designing requirement, this matter will also directly affect the quality ofstamping parts, such as the appearance quality, assembled performance, and reliability, etc.Therefore, the control of springback parts in hydrodynamic torque converter is the maindesign problem. Traditionally, researchers use the method called the scene of “trial anderror”-based on experiences to adjust the forming process parameters and amend the die-face, however, this method wastes lots of resources, and the production period is also toolong. Therefore, we mainly have two difficulties in the practical industry, one is how topredict the shape of hydrodynamic torque converter after springback, and the other is how todesign the die-face for compensating springback accurately.In the process of designing stamping welded hydrodynamic torque converter, thereliability of the whole structure is the key to ensure the secure operation. Therefore, in orderto test whether it reaches the requirements of hydrodynamic torque converter, we shouldcheck the welding strength of blade with core and shell based on the existing material,structure and designing condition.According to the above questions, this paper, relied on the projects “Development onflat hydrodynamic torque converter of car (2008C01036-4)” of Science and TechnologyAgency of Zhejiang Province, mainly focuses on the technical problem of designing andmanufacturing of stamping welded hydrodynamic torque converter, and will discuss deeplyabout the stamping forming of stamping welded hydrodynamic torque converter. The mainresearch contents contain:1. The stamping forming theory of torque converter and basic parameters testBased on elastic-plastic deformation theory, investigate the finite element theory ofstamping forming for hydrodynamic torque converter, analyze the main factors influencingthe bending springback of sheet metal, and also provide theoretical basis for the subsequentforming simulation of hydrodynamic torque converter; use the sheet tensile test on materialof making torque converter blade to get the basic parameters of mechanical properties ofmaterials, and then provide the evidence of the selection of material parameters in numericalsimulation; apply the torque converter blade material in the stamping forming numericalsimulation for the simple V type parts, and then test the certification of numerical simulationin order to lay a foundation for the following numerical simulation of stamping forming onstamping welded hydrodynamic torque converter.2. The forming simulation of stamping welded hydrodynamic torque converterBased on the empirical formula and the circulation distribution method, design a simplemodel of YJH255stamping welded hydrodynamic torque converter. In order to improve the utilization rate of materials, apply the finite element inverse algorithm to the blank unfoldingcalculation of hydrodynamic torque converter, and then get the shape and size of blankmaterial; numerically simulate the stamping forming of torque converter blank unfolded, andanalyze the forming results, and finally predict the springback that may appears in the actualproducing process, this would provide the evidence of using springback rules in die-facecompensation.3. The blade springback compensation and die designThe shape of stamping welded hydrodynamic torque converter blade is complicated, soit needs a high precision of manufacturing. The shape of the blade determines theperformance of torque converter and needs to be the same as the real product, so we need tocompensate the springback value of torque converter blade. To get the best forming processparameters, we test the springback value on three-dimensional space twisted blade byorthogonal test method; Use die-face compensation method on hydrodynamic torqueconverter blade to correct springback; Considering to meet the design requirements of thedie-face of blade, core and shell in a hydrodynamic torque converter, we use3D modelingsoftware UG to parametric design, and then fast generates3D models for the dies, finally, getthe real product of hydrodynamic torque converter.4. Test and comparative analysis the forming of hydrodynamic torque converterBecause the blade of torque converter is spatial distortion surface, so in order to verifythe effectiveness of the springback compensation method, we choose to scan and test thedesigned stamping welded hydrodynamic torque converter prototype by ATOS non-contactoptical scanner, and then test the forming precision. Meanwhile, we will also test the externalcharacteristics of the hydrodynamic torque converter, and then examine the performance ofthe hydrodynamic torque converter.5. The welding strength analysis of blade with core and shell on stamping weldedhydrodynamic torque converterBased on the fluid-solid interaction (FSI) analysis technology, we analyze the weldingstrength on the designed blade with core and shell of hydrodynamic torque converter. Firstly,numerical calculate CFD on flow field of torque converter working chamber by the fluid analysis software FLUENT; Secondly, apply the results about the fluid pressure load in thecoupling surface mapping onto the impeller structure surface by the method of gridinterpolation mapping; Finally, use finite element analysis software ANSYS to calculate theFSI welding strength of impeller structure of hydrodynamic torque converter.This paper discusses the stamping forming theory and numerical simulation methods ofstamping welded hydrodynamic torque converter. These theories and methods effectivelysolve the technical problems in production, promote the die technology of hydrodynamictorque converter, and also reduce production cost and cycle. Moreover, this paper hasimportant theory guiding significance and practical value to manufacture of stamping weldedhydrodynamic torque converter, and provides references for the development of newproducts of hydrodynamic torque converter, and also provides a better foundation for theindependent research in Chinese automobile industry.